Ok so tried roverguy7's idea and as I said before the same thing happened. Changing the passenger side to cold produced cold. But regardless, the driver side still remained cold (room temperature-ish). Someone mentioned SDD, what is that? I am assuming its software and requires a mechanic of some sort. Like I said my battery went dead around the same time as the heater core.

 

SDD is Symptom Driven Diagnostics and is a brand name for a type of software that Jaguar Land Rover uses in their T4 units. It is an upgrade from IDS, Integrated Diagnostic Software. The software is installed in something like the dealer T4 and talks to the heating system. The real problem is you have to know how to interpret what the T4 or whatever says; just having the equipment and software is not enough.

Below is a link to a number of files on the heater and AC systems. There is one 21 page pdf that may be of some help. The real problem is that as you know, it is near impossible to get at or into the heater to replace anything.

In this case, it is very possible that one of the four air doors is not cycling; perhaps the air mix blend motor or the foot well stepper motor.

As to replacing the heater core, while a bad time to ask, perhaps the heater core was OK and all along it has been a stepper motor. Alternatively, when the heater core was replaced, perhaps some of the stepper motor linkage was not put back together correctly or a motor has since quit.

I note you mention air lock. Do not rule out an air lock.

Sometimes this hard to diagnose problem is something simple. Getting the air out of the cooling system after just a thermostat change is near impossible it seems; hence an air lock in the heater makes a lot of sense.

If it was an air lock or a blend door linkage problem, no electronic test would show that as the motor is OK, it just does not do the correct things in the correct order. Air lock problems are not in the software so there could never be a message to that effect.

As to how one figures that out, I do not really know other than patiently pushing those 3 buttons on the left side of the control panel and seeing if there is a pattern to them that does not make sense. The material on the link may help.

Below is as best I could find for the part numbers for the stepper motors. Each costs from fifty to a hundred dollars.

The motors may or may not look the same, but as below, all have different part numbers.

(19E616A) Recirculation JNC500010, now new part number JNC500040 for LHD
JNC500020, now new part number JNC500050 for RHD;

The other 3 motors below, where the steering wheel is, does not seem to matter.

(19E616B) Defrost Stepper JWO500010, now new part number LR041271

(19E616C) Footwell Stepper JWO500020, now new part number LR041272

(19E616D) Air Mix Blend JWO500030, now new part number LR041273


Re the battery, reagardless, put your battery on a trickle charger for about a week of nights. It takes a long time to get a LR battery to full charge. You can drive solid all day for a week and the battery will be perhaps 75%. I use a CTEK US3300 that charges at about 14.7 volts and 3.3 amps max.

DISCO3.CO.UK Photo Gallery - Heater Air Conditioner System

 

Update. I checked all the buttons to make sure air flow was appropriate and it is. Almost. When I select the floor flow, a tiny amount comes out on the divers side defrost vent. I mean very tiny amount. I left the filler cap open last night in hopes it would burp and free up any air. Still not real heat coming from the drivers side. I replaced the battery with a brand new one. It was time anyways. I am fairly certain the core was blown because I had an insane amount of coolant on my floorboards. When they replaced the core they did it without removing the entire dash, just a few parts to get inside so I don't think anything would have been damaged. So what are we thinking? Just keep trying to bleed? BTW, any tips on how to bleed it?

 

Well I guess that is good news then re the air exiting where it is supposed to. As to a bit of air leaking out from wherever, in the case of the defroster vents, it could even be that is intentional, however none of the air doors need be air tight so it is probably just normal air leakage you are feeling. That is good I guess.

As to how to bleed air from the cooling system, that I do not know other than it is near impossible.

There is a special air bleeder Tee under the black engine cover on a small half to 3/4 inch diameter hose. I would be using that and keeping the pressure up on the cooling system. I do not think having any caps off would do anything other than perhaps introducing more air into the system.

If you have the rear heater, is it working OK? The question I am really asking is water flowing to it?

When trying to bleed the air, have both of the temperature ***** full up in an attempt to maximize water flow. Have more of the official coolant available as the only way you will know if air was in the system is when you see the expansion tank low and then you will need to top it up - or distilled water is OK for all you will need. These days tap water is not the best any longer for these exotic alloy engines.

If you had a leak in the heat exchanger, yes, you needed a new one - at least that was simple then. It also sounds like the guys must have been midgets to replace the heater core without totally removing the interior of the 3. I think LR started with the heater and then installed the interior around it.

 

I have looked for this valve under the engine cover and cannot find it. I have to V8 model. Any pictures or diagram of it? I looked at a parts manual and cant see what everyone is talking about. I have heard of this "T" disintegrating on some people so I figured I would have a look. Cant find it. Judging by everything I am seeing and feeling. It has to be an air pocket trapped in the core still. The drivers side is pumping good heat and before the core was replaced I never had a problem with heat, It was just a little sluggish because I didn't know it was leaking. The coolant level has dropped over night since I left the cap off, so I am assuming it sucked a little in, maybe a small burp.

 

 

Can't find the "T" anywhere! I think you guys are all bonkers. I don't have the rear heater in mine so I am not sure if this is why I can't find this part. Regardless, I am not worried. What I am still trying to do is bleed more air out of the system to see if that helps. I cracked the bleeder next to the fill cap a little and give her some throttle with the heat on full blast hoping that will force some out.

 

To see the bleeder tee, you have to remove the black plastic engine cover first. There is a mess of little hoses on top of the engine. One of them is per the jpg below. The tee has a chrome screw cap sort of on towards the rear of the engine on the drivers side.

The hose also shows in one of those water piping sketches I attached in the previous email.

The bleeder is not related to the second heater so that is not the problem; it is possible the tee was removed by someone else I suppose and is now just a straight connector?

And yes, probably most LR owners are a bit bonkers.

 

Yep, after looking at some older posts, I found a pic of what I was looking for with the engine and sure enough, it do not have this piece. Someone replaced it and it is now one solid hose. So looks like I am short one bleeder. I did find another post (https://plus.google.com/photos/+Gerr...12215323848801) that shows a great way to bleed the system and I am sure you have seen this one too. I do not have that bleeder nor the vac to do this however. So here is a thought, turning the A/C on blast causing the engine to work harder and the T-stat also, moderate throttle with the bleeder valve next to the fill cracked a little? Think I can get some air to burp?

 

Somehow turning the AC on I do not think will achieve the desired goal. At least there seems to be general agreement that getting the air out is near impossible.

I think I might purchase a some 5/16" or 3/8" brass fittings, cut that little hose and install my own breather.

Then you can get a suitable length of hose and run it off the tee back to the expansion tank cap. Fit the hose to a a radiator petcock or some sort of valve right off the tee and you would have pretty good control and no mess.

You could bleed for hours at idle and do it again day after day without too much fuss.

Doing this sort of fix year after year is why one goes bonkers.